<script type="text/javascript">
function hexColor(styleColor) {
var dec, hex = styleColor;
if (dec = hex.match(/^rgb\(([0-9]+), *([0-9]+), *([0-9]+)\)$/)) {
hex = (1*dec[3] + 256*dec[2] + 65536*dec[1]).toString(16);
while(hex.length<6) hex = "0"+hex;
hex = "#"+hex
}
return hex;
}
</script>
<div id="teste" style="color: #0033FF;">POUETTE</div>
<input type="button" onclick="alert(hexColor(document.getElementById('teste').style.color))" value="hexColor(style.color)">